The present invention relates to a graphic display device, more particularly, to a graphic printer system that can process graphs by using simple and high-speed blinking means.
Conventionally, any of the existing graphic display devices provides a display memory that deals with individual dots on the CRT display screen on a 1:1 basis, while the display device reads the graphic pattern of the display memory synchronously with the raster scan and sends the pattern to the display driver circuit so that a specific graph can be output onto the CRT display screen. When writing a graphic pattern into the display memory, a specific graphic data is drawn out of data memory storing graphic data under the CPU control, which is then sent to the graphic display controller (GDC), in which, said data is developed into a graphic dot pattern before said pattern is stored in the display memory. The conventional practice is to cause the graphic pattern on the CRT display screen to perform blinking so that the operator will pay attention to it. Generally, when causing a graphic pattern to blink, such an existing device must perform a complex process for causing the pattern to be stored in said display memory before blinking, i.e., it has to rewrite dots corresponding to the designated patterns into "1" and " 0" in every blinking cycle.